A pulse tracer test was performed with an

initial concentration of $5\mathrm{.}6$ mg$/$L$,$ and the

following data were collected

ime $($min$)$: $48,54\mathrm{.}9,61\mathrm{.}7,68\mathrm{.}6,75\mathrm{.}5,$

$82\mathrm{.}3,89\mathrm{.}2,96,103,110,117,123$

conc. $($mg$/$L$)$: $5\mathrm{.}6,6\mathrm{.}49,19\mathrm{.}8,85\mathrm{.}3,190,$

$213,132,52\mathrm{.}4,16\mathrm{.}2,7\mathrm{.}22,5\mathrm{.}77,5\mathrm{.}62$What is the normalization concentration, CN $,$

of the tracer test?

Your answer must be within $\backslash$pm $5\mathrm{.}0\%$